Segments and Operations by Geographic Area (Schedule of Significant Customers, Revenue Concentration) (Details)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
At T [Member]
Segment Reporting Information [Line Items]
Segment reporting, disclosure of major customers	The Company's relationship with AT&T is based upon master service agreements, other service agreements and construction/installation contracts for both AT&T's wireless and wireline infrastructure businesses. Revenue from AT&T is included in the Communications segment.
Direct Tv [Member]
Segment Reporting Information [Line Items]
Segment reporting, disclosure of major customers	The Company's relationship with DIRECTV® is based upon an agreement to provide installation and maintenance services for DIRECTV®. Revenue from DIRECTV® is included in the Communications segment.
Enbridge [Member] [Domain]
Segment Reporting Information [Line Items]
Segment reporting, disclosure of major customers	The Company's relationship with Enbridge, Inc. is based upon a construction contract for natural gas pipelines. Revenue from Enbridge, Inc. is included in the Oil and Gas segment.
Segment, Continuing Operations [Member] | Reportable Segment [Member] | Communications [Member] | Customer Concentration Risk [Member] | At T [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	18.00%	19.00%
Segment, Continuing Operations [Member] | Reportable Segment [Member] | Communications [Member] | Customer Concentration Risk [Member] | Direct Tv [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	16.00%	20.00%
Segment, Continuing Operations [Member] | Reportable Segment [Member] | Oil and Gas [Member] | Customer Concentration Risk [Member] | Enbridge [Member] [Domain]
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	12.00%	0.00%